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IBM CICS and the Coupling Facility: Beyond the Basics

Book Description

Abstract

It's easy to look at the title of a book and think "that's old news" or "I already know all there is to know on that subject." But before you dismiss this publication, consider just how far the IBM® Parallel Sysplex® architecture has come. From the early days the mainframe has embraced a shared everything approach. The original designers coded IBM z/OS® (called IBM MVS™ or IBM OS/390® back then) with the functionality necessary for the operating system to create the repositories, manage the data flow, and ensure the integrity of the systems involved. From there, the middleware systems provided the exploitation and advanced functions to mature the technology. The component in the middle of all this great technology can easily be taken for granted. That is the IBM Coupling Facility.

This IBM Redbooks® publication discusses both traditional uses for the IBM Coupling Facility technology and new ways to use it with products such as IBM CICS®. You can learn how to perform new functions and have these functions benefit from the scalability and availability achieved only in a mainframe ecosystem.

Open standards are a large part of considerations today, as most companies run IT shops with a mix of technology components. As the world embraces these technologies, it is necessary to understand how to mix the world of mainframe architectures and products with other open architectures. This mix allows the best tool to be used to solve processing needs, at the right cost and service levels.

Often the functions needed for modern processing can be found in house, in places where staff are skilled and that already deliver the robust production environments you count on daily. This book discusses these modern functions and how to achieve them with CICS use of the IBM Coupling Facility. You will learn how one IBM client, Walmart, took these concepts far beyond the original design as they share their experiences and even share code examples to help you get started.

The last chapter of this book shows what can be achieved when a combination of old and new functions are use together. Even if you have familiarity with what could be done with the IBM Coupling Facility in the past, there is much to learn and deploy in a modern world.

Those who are familiar with the IBM Coupling Facility might find the content of this book helpful. Additionally, readers who are considering how to use the IBM Coupling Facility technology within their environment might also find useful information in the chapters that follow

Table of Contents

  1. Front cover
  2. Notices
    1. Trademarks
  3. Preface
    1. Authors
    2. Now you can become a published author, too!
    3. Comments welcome
    4. Stay connected to IBM Redbooks
  4. Chapter 1. Understanding the IBM Coupling Facility
    1. 1.1 Coupling Facility defined
      1. 1.1.1 Coupling Facility structures
      2. 1.1.2 Coupling Facility placement
    2. 1.2 Historical uses of Coupling Facility structures
    3. 1.3 Newer functions of the CF structures
    4. 1.4 Benefits of reading this book
      1. 1.4.1 Design developer benefits
      2. 1.4.2 Application programmer benefits
      3. 1.4.3 System programmer benefits
    5. 1.5 Client experience
      1. 1.5.1 Walmart’s experience
      2. 1.5.2 Walmart’s references
    6. 1.6 Moving forward
  5. Chapter 2. VSAM record-level sharing
    1. 2.1 General use of VSAM RLS in CICS
    2. 2.2 Setting up VSAM RLS in CICS
      1. 2.2.1 Changes to CICS parameters to support RLS
      2. 2.2.2 Altering file definitions to enable RLS access
      3. 2.2.3 Application considerations when using RLS
    3. 2.3 Uses of VSAM RLS in CICS
      1. 2.3.1 Eliminating file owning regions
      2. 2.3.2 Improved scalability
  6. Chapter 3. Named counters
    1. 3.1 Common uses of named counters
    2. 3.2 Setting up named counters
      1. 3.2.1 Defining resources to the CF
      2. 3.2.2 Creating the named counter server
      3. 3.2.3 Changes to CICS to access the named counters server
      4. 3.2.4 Creating and accessing a named counter
    3. 3.3 Examples of named counter use
      1. 3.3.1 Generating a unique ID
      2. 3.3.2 Generating components of keys
      3. 3.3.3 Distributing the workload and resources
      4. 3.3.4 Tracking activity
  7. Chapter 4. Global resource serialization
    1. 4.1 Common uses of CICS global enqueues
    2. 4.2 Setting up global enqueues in CICS
    3. 4.3 Use cases for CICS global enqueues
      1. 4.3.1 Global transaction class
      2. 4.3.2 Serialization for dispatched tasks
      3. 4.3.3 Enqueue list
  8. Chapter 5. Coupling facility data tables
    1. 5.1 Common uses of CFDTs
    2. 5.2 Setting up CFDTs
      1. 5.2.1 Defining resources to the CF
      2. 5.2.2 Creating the CFDT server
      3. 5.2.3 Defining CFDTs in CICS
      4. 5.2.4 Accessing CFDTs
    3. 5.3 Examples of CFDT use
      1. 5.3.1 Caching information
      2. 5.3.2 Logging work items
      3. 5.3.3 Flexibility for data stores
  9. Chapter 6. Shared temporary storage
    1. 6.1 Common uses of temporary storage
    2. 6.2 Setting up shared temporary storage
      1. 6.2.1 Defining resources to the CF
      2. 6.2.2 Creating the shared TS server
      3. 6.2.3 Changes to CICS to access the shared TS server
    3. 6.3 Use cases for shared temporary storage
      1. 6.3.1 Adjusting priority based on HTTP method
      2. 6.3.2 Sharing data among tasks
  10. Chapter 7. Combined functional use
    1. 7.1 Affinities
    2. 7.2 Sequencing captured updates for data synchronization solution
      1. 7.2.1 CFDT and VSAM RLS data stores
      2. 7.2.2 Global resource serialization
    3. 7.3 Processing one-to-many parallel requests
      1. 7.3.1 Shared TS queues
      2. 7.3.2 GRS
      3. 7.3.3 CFDT
    4. 7.4 Tiered data store options
    5. 7.5 Assist parallelization of downstream processing
    6. 7.6 Using other CF resources
      1. 7.6.1 Shared queues
      2. 7.6.2 Workload Manager-managed sysplex distribution
    7. 7.7 Summary
  11. Back cover